scholarly journals Diffusion Tensor Imaging, White Matter Lesions, the Corpus Callosum, and Gait in the Elderly

Stroke ◽  
2009 ◽  
Vol 40 (12) ◽  
pp. 3816-3820 ◽  
Author(s):  
Refeeque A. Bhadelia ◽  
Lori Lyn Price ◽  
Kurtis L. Tedesco ◽  
Tammy Scott ◽  
Wei Qiao Qiu ◽  
...  
Neurosurgery ◽  
2011 ◽  
Vol 68 (6) ◽  
pp. 1586-1593 ◽  
Author(s):  
Niklas Lenfeldt ◽  
Anne Larsson ◽  
Lars Nyberg ◽  
Richard Birgander ◽  
Anders Eklund ◽  
...  

Abstract BACKGROUND: Idiopathic normal-pressure hydrocephalus (INPH) is associated with white matter lesions, but the extent and severity of the lesions do not cohere with symptoms or improvement after shunting, implying the presence of further, yet undisclosed, injuries to white matter in INPH. OBJECTIVE: To apply diffusion tensor imaging (DTI) to explore white matter lesions in patients with INPH before and after drainage of cerebrospinal fluid (CSF). METHODS: Eighteen patients and 10 controls were included. DTI was performed in a 1.5T MRI scanner before and after 3-day drainage of 400 mL of CSF. Regions of interest included corpus callosum, capsula interna, frontal and lateral periventricular white matter, and centrum semiovale. White matter integrity was quantified by assessing fractional anisotropies (FA) and apparent diffusion coefficients (ADC), comparing them between patients and controls and between patients before and after drainage. The significance level corresponded to .05 (Bonferroni corrected). RESULTS: Decreased FA in patients was found in 3 regions (P < .002, P < .001, and P < .001) in anterior frontal white matter, whereas elevated ADC was found in genu corpus callosum (P < .001) and areas of centrum semiovale associated with the precentral gyri (P < .002). Diffusion patterns in these areas did not change after drainage. CONCLUSION: DTI reveals subtle injuries—interpreted as axonal loss and gliosis—to anterior frontal white matter where high-order motor systems between frontal cortex and basal ganglia travel, further supporting the notion that motor symptoms in INPH are caused by a chronic ischemia to the neuronal systems involved in the planning processes of movements.


2017 ◽  
Author(s):  
András Jakab ◽  
Ruth O`Gorman Tuura ◽  
Christian Kellenberger ◽  
Ianina Scheer

AbstractOur purpose was to evaluate the within-subject reproducibility of in utero diffusion tensor imaging (DTI) metrics and the visibility of major white matter structures.Images for 30 fetuses (20-33. postmenstrual weeks, normal neurodevelopment: 6 cases, cerebral pathology: 24 cases) were acquired on 1.5T or 3.0T MRI. DTI with 15 diffusion-weighting directions was repeated three times for each case, TR/TE: 2200/63 ms, voxel size: 1*1 mm, slice thickness: 3-5 mm, b-factor: 700 s/mm2. Reproducibility was evaluated from structure detectability, variability of DTI measures using the coefficient of variation (CV), image correlation and structural similarity across repeated scans for six selected structures. The effect of age, scanner type, presence of pathology was determined using Wilcoxon rank sum test.White matter structures were detectable in the following percentage of fetuses in at least two of the three repeated scans: corpus callosum genu 76%, splenium 64%, internal capsule, posterior limb 60%, brainstem fibers 40% and temporooccipital association pathways 60%. The mean CV of DTI metrics ranged between 3% and 14.6% and we measured higher reproducibility in fetuses with normal brain development. Head motion was negatively correlated with reproducibility, this effect was partially ameliorated by motion-correction algorithm using image registration. Structures on 3.0 T had higher variability both with- and without motion correction.Fetal DTI is reproducible for projection and commissural bundles during mid-gestation, however, in 16-30% of the cases, data were corrupted by artifacts, resulting in impaired detection of white matter structures. To achieve robust results for the quantitative analysis of diffusivity and anisotropy values, fetal-specific image processing is recommended and repeated DTI is needed to ensure the detectability of fiber pathways.AbbreviationsADaxial diffusivity;CCAcorpus callosum agenesis;CVcoefficient of variation,DTIdiffusion tensor imaging;FAfractional anisotropy;GWgestational week;MDmean diffusivity;RDradial diffusivity;ROIregion of interest;SSIMstructural similarity index


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
John Conklin ◽  
Frank L Silver ◽  
David J Mikulis ◽  
Daniel M Mandell

INTRODUCTION: Leukoaraiosis, the presence of “incidental” white matter lesions in the aging brain, is increasingly recognized as a predictor for dementia, ischemic stroke, intracerebral hemorrhage and vascular death. The pathogenesis of leukoaraiosis remains controversial, with abnormalities of small arterioles hypothesized to play an important role. To investigate this hypothesis, we sought to characterize the temporal evolution of the individual lesions making up leukoaraiosis. HYPOTHESIS: Discrete occlusive events at the level of small arterioles play a key role in the pathogenesis of leukoaraiosis. METHODS: Participants were prospectively recruited through an outpatient neurology clinic (inclusion criteria: age > 60 years, Fazekas grade 3 leukoaraiosis burden; exclusion criteria: cortical infarct, cardioembolic disease, dissection, carotid stenosis > 50%). Subjects underwent an identical MRI protocol in each of 16 consecutive weeks, including diffusion tensor imaging (DTI) and multi-echo T2-weighted imaging. Parametric maps of the apparent diffusion coefficient (ADC), fractional anisotropy (FA) and T2 relaxation time were constructed and coregistered (Analysis of Functional NeuroImages, NIH; 3D Slicer, www.slicer.org; Matlab, The MathWorks). Images were reviewed for new diffusion restricting lesions, and such lesions were manually segmented. Plots of lesion ADC, FA and T2 were generated and temporally aligned to the onset of acute diffusion restriction. RESULTS: Five subjects (mean age 69 ± 8 years) met criteria and completed all 16 MRI scans. There were no lacunar or large artery infarcts during the study period. A total of 9 new diffusion restricting white matter lesions were identified (mean volume 0.06 ± 0.03 cc). Evolution of these lesions showed striking similarity to that of cerebral infarction, with acute reduction in ADC, followed by gradual rise in ADC and T2, and corresponding decline in FA. At 8 weeks, new lesions were indistinguishable from pre-existing white matter disease. CONCLUSION: Leukoaraiosis evolves through temporally and spatially discrete acute ischemic injuries. This supports the hypothesized role of small vessel arteriolar pathology as a key pathogenetic mechanism.


2008 ◽  
Vol 14 ◽  
pp. S12
Author(s):  
K.F. De Laat ◽  
A.G.W. Van Norden ◽  
R.A.R. Gons ◽  
L.J.B. Van Oudheusden ◽  
I. Van Ouden ◽  
...  

2008 ◽  
Vol 14 ◽  
pp. S12-S13
Author(s):  
R.A.R. Gons ◽  
K.F. De Laat ◽  
A.G.W. Van Norden ◽  
L.J.B. Van Oudheusden ◽  
M.P. Zwiers ◽  
...  

2014 ◽  
Vol 20 (14) ◽  
pp. 1904-1907 ◽  
Author(s):  
Michael Scheel ◽  
Carsten Finke ◽  
Timm Oberwahrenbrock ◽  
Alina Freing ◽  
Luisa-Maria Pech ◽  
...  

We investigated the association of retinal nerve fibre layer thickness (RNFL) with white matter damage assessed by diffusion tensor imaging (DTI). Forty-four MS patients and 30 healthy subjects underwent optical coherence tomography. DTI was analysed with a voxel-based whole brain and region-based analysis of optic radiation, corpus callosum and further white matter. Correlations between RNFL, fractional anisotropy (FA) and other DTI-based parameters were assessed in patients and controls. RNFL correlated with optic radiation FA, but also with corpus callosum and remaining white matter FA. Our findings demonstrate that RNFL changes indicate white matter damage exceeding the visual pathway.


PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e59108 ◽  
Author(s):  
Jim Lagopoulos ◽  
Daniel F. Hermens ◽  
Sean N. Hatton ◽  
Juliette Tobias-Webb ◽  
Kristi Griffiths ◽  
...  

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